Corpus-NZ/Code-Syntax-Expanded · Datasets at Hugging Face

wrong_code stringlengths 3 123	correct_code stringlengths 3 155	explanation stringclasses 101 values	language stringclasses 26 values
for i=1,38 do print(i) end	for i=1,38 do print(i) end	Correct.	Lua
<?php // code ?>	<?php // code ?>	Correct.	PHP
{ "name": "result" }	{ "name": "result" }	Correct.	JSON
match x {{ 1 => {{}} }}	match x {{ 1 => {{}} _ => {{}} }}	Match must be exhaustive.	Rust
if x = 70 then print('result') end	if x == 70 then print('result') end	Use ==.	Lua
let text1 = String::from("world"); let text2 = text1; println!("{{}}", text1);	let text1 = String::from("world"); let text2 = text1.clone(); println!("{{}}", text1);	Clone to avoid move.	Rust
int values[50]; values[50]=5;	int values[50]; if(50<50){{}} else values[50]=5;	Bounds check.	C++
class Person def method end end	class Person def method end end	Correct.	Ruby
<div color=#333>	<div style='color:#333;'>	Use style attribute.	CSS
let msg = String::from("info"); let r=&msg; msg.push_str("!");	let mut msg = String::from("info"); let r=&msg; println!("{{}}", r); msg.push_str("!");	Cannot mutate while borrowed.	Rust
echo data world	echo 'data world'	Quote to prevent splitting.	Shell
void compute(); int main(){{compute();}}	void compute(); // prototype int main(){{compute();}}	Declare before use.	C++
while read line; do echo $line; done < config.json	while read line; do echo $line; done < config.json	Correct.	Shell
let num = 10; num += 1;	let mut num = 10; num += 1;	Need mut to modify.	Rust
print 'hello'	print('hello')	print needs parentheses.	Python
num == '36'	num === 36	Use strict equality.	JavaScript
process	process()	Add parentheses.	Kotlin
<div color=blue>	<div style='color:blue;'>	Use style attribute.	CSS
List<int> list = [1,2,3];	List<int> list = [1,2,3];	Correct.	Dart
with open('log.txt') as f: data = f.read()	with open('log.txt') as f: data = f.read()	Correct.	Python
{{'status':'output'}}	{{"status":"output"}}	Use double quotes.	JSON
[21, 35, 67	[21, 35, 67]	Close bracket.	Python
val x = 44; x = 79	var x = 44; x = 79	Use var for reassignment.	Scala
["message", 22]	["message", 22]	Correct.	JSON
if (z = 14) {}	if (z == 14) {}	Use ==.	Dart
x <- 5; if (x > 3) print('large')	x <- 5; if (x > 3) print('large')	Correct.	R
<input type='text' value='world'>	<input type='text' value='world' name='status'>	Add name attribute.	HTML
'world' + 39	'world' + 39.to_s	Convert int.	Ruby
if ($bar = 22)	if ($bar == 22)	Use ==.	Perl
assert y > 2	assert y > 2	Correct.	Python
while read line; do echo $line; done < data.txt	while read line; do echo $line; done < data.txt	Correct.	Shell
let foo: number \| null = null; foo.toFixed(45);	let foo: number \| null = null; if(foo!==null) foo.toFixed(45);	Null check.	TypeScript
let vec=vec![19,34,55]; let primary=&vec[0]; vec.push(31);	let mut vec=vec![19,34,55]; let primary=vec[0]; vec.push(31);	Copy instead of reference.	Rust
def compute(): print('message')	def compute(): print('message')	Indent function body.	Python
UPDATE users SET status='message' WHERE status=17	UPDATE users SET status='message' WHERE status=17;	Add semicolon.	SQL
function handle(index:string){{return index;}} handle(84);	function handle(index:string){{return index;}} handle('hello');	Pass correct type.	TypeScript
.Person {{ color: red; }}	.Person {{ color: red; }}	Correct.	CSS
if (index = 92) {{}}	if (index == 92) {{}}	Use ==.	Java
os.sqrt(2)	import os os.sqrt(2)	Import module first.	Python
if (x = 100) {{}}	if (x == 100) {{}}	Use ==.	Kotlin
let x: Int = 'info'	let x: String = 'info'	Fix type.	Swift
type MyType = string \| number; let x: MyType = true;	type MyType = string \| number; let x: MyType = 'hello';	Type not in union.	TypeScript
int &ref;	int x; int &ref = x;	Reference must be initialized.	C++
if [ $bar = 76 ]; then	if [ "$bar" = 76 ]; then	Quote variable.	Shell
class Person {{ int y; }};	class Person {{ public: int y; }};	Make public.	C++
for y in range(50) print(y)	for y in range(50): print(y)	Colon after for.	Python
WHERE status = '8'	WHERE status = 8	Don't quote integer.	SQL
SELECT name status FROM users;	SELECT name, status FROM users;	Add comma.	SQL
yield c	yield c	Correct yield.	Python
INSERT INTO items VALUES ('test',97)	INSERT INTO items (name, email) VALUES ('test',97);	Specify columns.	SQL
DELETE FROM products WHERE status=29	DELETE FROM products WHERE status=29;	Add semicolon.	SQL
for i=1,28 do print(i) end	for i=1,28 do print(i) end	Correct.	Lua
x = 5; if x > 3, disp('large'), end	x = 5; if x > 3, disp('large'), end	Correct.	MATLAB
for i in $(ls); do echo $i; done	for i in $(ls); do echo $i; done	Correct.	Shell
print('test')	print('test')	Correct.	R
<div><p>output</div></p>	<div><p>output</p></div>	Nest properly.	HTML
SELECT * FROM users WHRE age=57;	SELECT * FROM users WHERE age=57;	Fix WHERE.	SQL
if (z = 53) {{}}	if (z === 53) {{}}	Use === for equality.	JavaScript
else print('test')	else: print('test')	Colon after else.	Python
<img src='message.jpg'>	<img src='message.jpg' alt='desc'>	Add alt text.	HTML
echo 'data'	echo 'data';	Add semicolon.	PHP
try {{ throw 'result'; }} catch(e) {{}}	try {{ throw new Error('result'); }} catch(e) {{}}	Throw Error objects.	JavaScript
const y = 53; y = 10;	let y = 53; y = 10;	Cannot reassign const.	JavaScript
val b: Int = 'value'	val b: String = 'value'	Fix type.	Kotlin
values.forEach(function(y) {{ console.log(y); }})	values.forEach((y) => {{ console.log(y); }})	Arrow functions are cleaner.	JavaScript
void main() {{ print('data') }}	void main() {{ print('data'); }}	Add semicolon.	Dart
const user:Person = {{name:'world'}};	const user:Person = {{name:'world', age:67}};	Add missing property.	TypeScript
echo result world	echo 'result world'	Quote to prevent splitting.	Shell
match b {{ 1 => {{}} }}	match b {{ 1 => {{}} _ => {{}} }}	Match must be exhaustive.	Rust
System.out.println('test')	System.out.println('test');	Add semicolon.	Java
for (int i=0; i<18; i++) {{}}	for (int i=0; i<18; i++) {{}}	Correct.	Java
class User {{ int data; }} obj.data=5;	class User {{ public int data; }} obj.data=5;	Make field public.	Java
print 'hello'	print('hello')	Parentheses for function call.	Lua
fn bar() -> i32 {{ 16 }}	fn bar() -> i32 {{ 16 }}	Correct.	Rust
jwt.sign({{id:35}}, 'secret');	jwt.sign({{id:35}}, 'secret', {{expiresIn:'30m'}});	Add expiration.	Node.js
if item > 89 puts 'hello'	if item > 89 puts 'hello' end	Add 'end'.	Ruby
p {{ color: green }}	p {{ color: green; }}	Add semicolon.	CSS
if result = 69 then print('output') end	if result == 69 then print('output') end	Use ==.	Lua
h1 {{ font-size:8px color:blue; }}	h1 {{ font-size:8px; color:blue; }}	Add semicolon.	CSS
package main func main() {{}}	package main import 'fmt' func main() {{}}	Import needed.	Go
let s1 = String::from("message"); let str2 = s1; println!("{{}}", s1);	let s1 = String::from("message"); let str2 = s1.clone(); println!("{{}}", s1);	Clone to avoid move.	Rust
if (index = 39)	if (index == 39)	Use ==.	R
x := 9	x := 9	Correct.	Go
var x = 5; x = "hello"	var x = "hello"	Type mismatch.	Swift
println('info')	println("info")	Double quotes.	Scala
switch(result){{ case 7: break; }}	switch(result){{ case 7: break; default: break; }}	Add default case.	Java
$x = 5; print $x	$x = 5; print $x;	Missing semicolon.	Perl
<center>result</center>	<div style='text-align:center;'>result</div>	Use CSS.	HTML
local item = 39	local item = 39	Correct.	Lua
const bar;	const bar = 63;	Initialize const.	JavaScript
items[37]	if (length(items) >= 37) items[37]	Check length.	R
var a int = 'info'	var a string = 'info'	Type mismatch.	Go
<br></br>	<br>	Self-closing.	HTML
while a > 13 a -= 1	while a > 13: a -= 1	Colon missing after while.	Python
{{'name':8, 'value' 62}}	{{'name':8, 'value':62}}	Colon missing.	Python
const int x; x = 5;	const int x = 5;	Const must be initialized.	C++
<ul><li>test<li>hello</ul>	<ul><li>test</li><li>hello</li></ul>	Close li.	HTML
Product.save();	Product.save().then(()=>{{}}).catch(err=>{{}});	Handle promise.	Node.js
class Child Model:	class Child(Model):	Inheritance uses parentheses.	Python
$x = 5; echo $x	$x = 5; echo $x;	Missing semicolon.	PHP

for i=1,38 do print(i) end

Correct.

Lua

<?php // code ?>

Correct.

PHP

{ "name": "result" }

Correct.

JSON

match x {{ 1 => {{}} }}

match x {{ 1 => {{}} _ => {{}} }}

Match must be exhaustive.

Rust

if x = 70 then print('result') end

if x == 70 then print('result') end

Use ==.

Lua

let text1 = String::from("world"); let text2 = text1; println!("{{}}", text1);

let text1 = String::from("world"); let text2 = text1.clone(); println!("{{}}", text1);

Clone to avoid move.

Rust

int values[50]; values[50]=5;

int values[50]; if(50<50){{}} else values[50]=5;

Bounds check.

C++

class Person def method end end

Correct.

Ruby

Use style attribute.

CSS

let msg = String::from("info"); let r=&msg; msg.push_str("!");

let mut msg = String::from("info"); let r=&msg; println!("{{}}", r); msg.push_str("!");

Cannot mutate while borrowed.

Rust

echo data world

echo 'data world'

Quote to prevent splitting.

Shell

void compute(); int main(){{compute();}}

void compute(); // prototype int main(){{compute();}}

Declare before use.

C++

while read line; do echo $line; done < config.json

Correct.

Shell

let num = 10; num += 1;

let mut num = 10; num += 1;

Need mut to modify.

Rust

print 'hello'

print('hello')

print needs parentheses.

Python

num == '36'

num === 36

Use strict equality.

JavaScript

process

process()

Add parentheses.

Kotlin

Use style attribute.

CSS

List<int> list = [1,2,3];

Correct.

Dart

with open('log.txt') as f: data = f.read()

Correct.

Python

Use double quotes.

JSON

[21, 35, 67

[21, 35, 67]

Close bracket.

Python

val x = 44; x = 79

var x = 44; x = 79

Use var for reassignment.

Scala

["message", 22]

Correct.

JSON

if (z = 14) {}

if (z == 14) {}

Use ==.

Dart

x <- 5; if (x > 3) print('large')

Correct.

R

Add name attribute.

HTML

'world' + 39

'world' + 39.to_s

Convert int.

Ruby

if ($bar = 22)

if ($bar == 22)

Use ==.

Perl

assert y > 2

Correct.

Python

while read line; do echo $line; done < data.txt

Correct.

Shell

let foo: number | null = null; foo.toFixed(45);

let foo: number | null = null; if(foo!==null) foo.toFixed(45);

Null check.

TypeScript

let vec=vec![19,34,55]; let primary=&vec[0]; vec.push(31);

let mut vec=vec![19,34,55]; let primary=vec[0]; vec.push(31);

Copy instead of reference.

Rust

def compute(): print('message')

Indent function body.

Python

UPDATE users SET status='message' WHERE status=17

UPDATE users SET status='message' WHERE status=17;

Add semicolon.

SQL

function handle(index:string){{return index;}} handle(84);

function handle(index:string){{return index;}} handle('hello');

Pass correct type.

TypeScript

.Person {{ color: red; }}

Correct.

CSS

if (index = 92) {{}}

if (index == 92) {{}}

Use ==.

Java

os.sqrt(2)

import os os.sqrt(2)

Import module first.

Python

if (x = 100) {{}}

if (x == 100) {{}}

Use ==.

Kotlin

let x: Int = 'info'

let x: String = 'info'

Fix type.

Swift

type MyType = string | number; let x: MyType = true;

type MyType = string | number; let x: MyType = 'hello';

Type not in union.

TypeScript

int &ref;

int x; int &ref = x;

Reference must be initialized.

C++

if [ $bar = 76 ]; then

if [ "$bar" = 76 ]; then

Quote variable.

Shell

class Person {{ int y; }};

class Person {{ public: int y; }};

Make public.

C++

for y in range(50) print(y)

for y in range(50): print(y)

Colon after for.

Python

WHERE status = '8'

WHERE status = 8

Don't quote integer.

SQL

SELECT name status FROM users;

SELECT name, status FROM users;

Add comma.

SQL

yield c

Correct yield.

Python

INSERT INTO items VALUES ('test',97)

INSERT INTO items (name, email) VALUES ('test',97);

Specify columns.

SQL

DELETE FROM products WHERE status=29

DELETE FROM products WHERE status=29;

Add semicolon.

SQL

for i=1,28 do print(i) end

Correct.

Lua

x = 5; if x > 3, disp('large'), end

Correct.

MATLAB

for i in $(ls); do echo $i; done

Correct.

Shell

print('test')

Correct.

R

<div><p>output</div></p>

<div><p>output</p></div>

Nest properly.

HTML

SELECT * FROM users WHRE age=57;

SELECT * FROM users WHERE age=57;

Fix WHERE.

SQL

if (z = 53) {{}}

if (z === 53) {{}}

Use === for equality.

JavaScript

else print('test')

else: print('test')

Colon after else.

Python

Add alt text.

HTML

echo 'data'

echo 'data';

Add semicolon.

PHP

try {{ throw 'result'; }} catch(e) {{}}

try {{ throw new Error('result'); }} catch(e) {{}}

Throw Error objects.

JavaScript

const y = 53; y = 10;

let y = 53; y = 10;

Cannot reassign const.

JavaScript

val b: Int = 'value'

val b: String = 'value'

Fix type.

Kotlin

values.forEach(function(y) {{ console.log(y); }})

values.forEach((y) => {{ console.log(y); }})

Arrow functions are cleaner.

JavaScript

void main() {{ print('data') }}

void main() {{ print('data'); }}

Add semicolon.

Dart

const user:Person = {{name:'world'}};

const user:Person = {{name:'world', age:67}};

Add missing property.

TypeScript

echo result world

echo 'result world'

Quote to prevent splitting.

Shell

match b {{ 1 => {{}} }}

match b {{ 1 => {{}} _ => {{}} }}

Match must be exhaustive.

Rust

System.out.println('test')

System.out.println('test');

Add semicolon.

Java

for (int i=0; i<18; i++) {{}}

Correct.

Java

class User {{ int data; }} obj.data=5;

class User {{ public int data; }} obj.data=5;

Make field public.

Java

print 'hello'

print('hello')

Parentheses for function call.

Lua

fn bar() -> i32 {{ 16 }}

Correct.

Rust

jwt.sign({{id:35}}, 'secret');

jwt.sign({{id:35}}, 'secret', {{expiresIn:'30m'}});

Add expiration.

Node.js

if item > 89 puts 'hello'

if item > 89 puts 'hello' end

Add 'end'.

Ruby

p {{ color: green }}

p {{ color: green; }}

Add semicolon.

CSS

if result = 69 then print('output') end

if result == 69 then print('output') end

Use ==.

Lua

h1 {{ font-size:8px color:blue; }}

h1 {{ font-size:8px; color:blue; }}

Add semicolon.

CSS

package main func main() {{}}

package main import 'fmt' func main() {{}}

Import needed.

Go

let s1 = String::from("message"); let str2 = s1; println!("{{}}", s1);

let s1 = String::from("message"); let str2 = s1.clone(); println!("{{}}", s1);

Clone to avoid move.

Rust

if (index = 39)

if (index == 39)

Use ==.

R

x := 9

Correct.

Go

var x = 5; x = "hello"

var x = "hello"

Type mismatch.

Swift

println('info')

println("info")

Double quotes.

Scala

switch(result){{ case 7: break; }}

switch(result){{ case 7: break; default: break; }}

Add default case.

Java

$x = 5; print $x

$x = 5; print $x;

Missing semicolon.

Perl

<center>result</center>

<div style='text-align:center;'>result</div>

Use CSS.

HTML

local item = 39

Correct.

Lua

const bar;

const bar = 63;

Initialize const.

JavaScript

items[37]

if (length(items) >= 37) items[37]

Check length.

R

var a int = 'info'

var a string = 'info'

Type mismatch.

Go

<br>

Self-closing.

HTML

while a > 13 a -= 1

while a > 13: a -= 1

Colon missing after while.

Python

Colon missing.

Python

const int x; x = 5;

const int x = 5;

Const must be initialized.

C++

<ul><li>test<li>hello</ul>

<ul><li>test</li><li>hello</li></ul>

Close li.

HTML

Product.save();

Product.save().then(()=>{{}}).catch(err=>{{}});

Handle promise.

Node.js

class Child Model:

class Child(Model):

Inheritance uses parentheses.

Python

$x = 5; echo $x

$x = 5; echo $x;

Missing semicolon.

PHP